Lecture 9 Functional Groups

Ch 10.5
Functional Groups
Definition Functional Groups
• Have specific name/formula/structure
• Carry out specific Rx
• Have specific characteristics
a) If they contain O, S, N: makes molecule polar,
higher MP/BP, soluble in water, liquid/solid at RT
b) If they contain C and H only: makes molecule
non-polar, low MP/BP, soluble in organic
solvents, gases at RT
Alk-anes, enes, ynes
• Hydrocarbons with single, double, triple bonds
• C-C or C=C or C=C
• Caution: add enough Hydrogen to fill remaining
covalent bonds
• CH3-CH3 or CH2=CH2 or CH=CH
Aromatic HC
• Molecules containing Benzene rings
• substituent called Phenyl
• Contain hydroxyl group
• - OH
Example: Ethanol
• Oxygen bridge in a carbon skeleton
• C-O-C
• Example: Diethyl ether
• Contain Carbonyl group: O double bonded to
Carbon C=O
• located at the end of Carbon skeleton
Example: Propanal
• Carbonyl at a center Carbon
Example: Propanone
• Contains Nitrogen
• Three different types of amines
• Primary – NH2 attached to 1 C and two H
• Secondary C-NH-C attached to two C and one H
• Tertiary
C-N-C attached to three C, no H!
• Raises pH of a solution
Carboxylic Acids
• Carboxyl =Alcohol and Carbonyl group at the
same carbon
• Lowers pH of solution!
• Example: Ethanoic Acid
Carboxylic Acid in the center of a molecule
Ethyl ethanoate
• Like Carboxyl group, OH replaced by NH2
• Ethanamide
• Thiol group
• -SH
• Ethane thiol